In-the-ear hearing aid



July 27, 1965 R. T. MARTIN 3,197,576

IN-THE-EAR HEARING AID Filed April 2, 1964 2 Sheets-Sheet 1 INVENTOR.

/9 .F1 c. 6 F710. 7 /9 R cnAno TMRn/v .AT TOR/VEYS July 27, 1965 R. T.MARTIN 3,197,576

IN-THE-EAR HEARING AID Filed April 2, 1964 2 Sheets-Sheet 2 INVENTOR.RICHARD TMRn/v BY Ea MW r AT TORNEYS United States Patent 3,197,576ihl-THEEAR HEARENG All) Richard T. Martin, Minneapolis, li r'inn,assignor to Dahlberg Electronics, inn, Minneapolis, Minn, a corporationof hiinnesota Apr. 2, Ser. No. 356,893 ll Claims. (Cl. 179-107) Thisinvention pertains to improvements in hearing aids, and moreparticularly to improvement in an inthe-ear hearing aid which isdesigned to be worn in the external ear of the user.

It is one object of the present invention to provide a miniaturizedhearing aid which fits completely in the ear of the user.

Another object of this invention is to provide a miniaturized hearingaid including a housing containing a microphone, amplifier and batteryand an elongated receiver member pivotally connected to said housing andadapted to be inserted in the ear canal of the user.

Still another object of this invention is to provide a miniaturizedhearing aid having a housing and an elongated receiver member and havingan improved means providing a pivotal connection between the receivermem- -er and the housing.

A further object of this invention is to provide a miniaturized hearingaid having an elongated receiver member for insertion in the ear canalof the user and having .a soft resilient tip fitted over the receivermember and shaped to the ear canal of the user to hold the receivermember therein.

Still another object of this invention is to provide a miniaturizedhearing aid having a compartmentized housing wherein a microphone andamplifier are each mounted in separate compartments separated by abattery compartment to provide isolation between the microphone andamplifier to reduce feed back effects.

A further object of thi invention is to provide a miniaturized hearingaid having an elongated receiver member capable of producing an acousticoutput from one end thereof, the receiver member being adapted forinsertion in the ear canal of the user with the acoustic output endadjacent the ear drum of the user, and a soft resilient tip fitted overthe receiver and fitted to the shape of the ear canal of the user tohold the receiver therein.

These and other objects of this invention will become apparent to thoseskilled in the art upon consideration of the accompanying specification,claims, and drawings.

Referring to the drawings, wherein like characters indicate like partsthroughout the several views:

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a sectional view taken along a line 22 of FIG. 1;

FIG. 3 is an exploded view of the present invention shown inperspective;

FIGS. 4-8 show various modifications of soft resilient tips which can befitted over the elongated receiver member of the hearing aid and shapedto the ear canal of the hearing aid user, parts thereof being brokenaway and shown in section.

Referring to the drawings, there is shown a hearing aid it) comprising ahousing 11 adapted to be worn in the external ear of the user, housing11 being divided into a first compartment 12, a center compartment 13,and a second end compartment 14,. End compartment 12 is separated fromcenter compartment 13 by a wall 15; While end compartment 14 isseparated from center compartment 13 by a wall 16.

An aperture 17 extends through an outer wall of housing 11 into endcompartment 12, aperture 17 having a grommet 2t? fitted therein. Grommet2% in turn has an aperture 21 therethrough. A microphone grill plate 18is positioned over aperture 17 on the outside of housing 11 and is heldin place by means of a cap 19.

An aperture 22 extends through a wall of housing 11 into end compartment12, aperture 22 having a screw driver adjust potentiometer 2-3 fittedtherein, the screw driver adjustment of potentiometer 23 being protectedby a cap 24. A microphone 25, having an acoustic input aperture 26, isshock mounted by means of rubber, or other suitable resilient supportingmembers, 27, and is positioned in end compartment 12 so that microphoneaperture 26 is adjacent aperture 21 of grommet 20. End compartment i2 issealed by means of the cover plate 30.

A first con-ducting plate 31 i clipped over wall 15 and extends alongthe face of wall 15 in center compartment 13, while a second conductingplate 32 is clipped over wall 16 and extends along wall 16 in the centercompartment 13. A generally arcuate, wafer type battery holder 33 ispivotally mounted between walls 15 and 16 and swings closed into centercompartment 13 of housing 11. Battery holder 33 is adapted to hold awafer type battery (not shown) which makes electrical contact with theconducting plates 31 and 32 when the battery compartment 33 is in aclosed position within the center compartment l3 of housing ll.

An amplifier circuit shown generally at 34, is mounted on a printedcircuit board 35. Amplifier 34 can be of any conventionalaudio-amplifier design and the details of a particular amplifier designare not shown. Amplifier 34 and printed circuit board 35 are mounted inend compartment 14 and are insulated from the conducting plate 32 bymeans of an insulating spacer 36. Suitable conducting means (not shown)connect the microphone 25 to the input of amplifier 34, and in additionconnect the battery conducting plates 31 and 32 to amplifier 34 toprovide an energizing source for the amplifier.

An elongated hollow boot 39 is formed from rubber, or other suitablesoft resilient material, and has an aperture it? at one end thereof andan aperture 41 at the opposite end thereof. Aperture end 41 of boot 39has a tapered neck portion which terminates in an external lip 42.

An elongated receiver member 4-3 has an acoustic output aperture 44 atone end thereof, receiver member 43 being capable of producing anacoustic output when energized. Receiver member 43 further hasenergizing terminals 4-5 and 4-6. The elongated receiver member 43 ismounted inside of the hollow resilient boot 39 so that the acousticoutput aperture 44 of receiver 43 i adjacent the aperture 46 of boot 39.The resilient boot-covered receiver 43 is adapted to be inserted in theear canal of the user so that the acoustic output aperture 44 ofreceiver 43 is adjacent the users eardrum. A rigid protection plate 47having flanged edges 43 is positioned in aperture 463 of boot 39, theflanged edges 48 of plate 47 being sandwiched between the end of boot 39and the end of receiver 43. Plate 47 has an aperture 49 therethrough,the axis of aperture 4) being generally perpendicular to the acousticoutput aperture 44 of receiver 43 and offset therefrom.

A wall plate 52 seals end compartment 14 of housing Ill. Plate 52 has anaperture 53 therethrough, the diameter of aperture 53 being les than thenormal diameter of the exterior lip 42 of boot 39. Since boot 39 ishighly resilient, the exterior lip 42 can be compressed and forcedthrough aperture 53 of Wall plate 52, boot 39 then being held in placeby exterior lip 42. A locking member 54 comprises a knob portion 55which i separated from one face of a plate as by means of a shaftportion 57. The maximum diameter of the knob portion 55 of lockingmember 5d is less than the diameter of aperture 53 of sueasre wall plate52 but is greater than the normal diameter of the aperture 41 of boot39. The diameter of the'shaft portion 5'7 of locking member 54 issubstantially equal to the diameter of the aperture 41 of boot member39. The diameter ofv the plate 56 of locking member 54- is greater thanthe diameter of aperture 53 of wall plate 52. Knob portion 55, shaftportion 57, and plate 56 are all axially aligned, and an aperture 58extends axially therethrough.

The knob portion 55 of locking member 54 is forced through the aperture41 of boot member 39' and hence locks the boot member 39 in position inaperture 53 of wall portion 52 by pinching the tapered portion of boot39 between shaft 57 of locking member 54 and the edge of aperture 53 ofwall plate 52. Since boot member 39 is highly resilient, it will be seenthat the boot 39'and receiver 43 are pivotally mounted in aperture 53 ofwall plate 52 and hence is free to move or pivot as the boot 3% isinserted in the ear canal of the user.

A first conductor 61 and a second conductor 62 are connected toenergizing terminals 45 and as of receiver 43, respectively, and extendthrough aperture 58 of locking member 54. and are connected to theoutput of amplifier 34.

In operatiomthe housing 11 of hearing aid it is worn in the exterior earof the user while the flexible boot 39 and receiver 43 are inserted inthe ear canal of the user so that aperture 48 of protection plate 4'7 isadjacent the users eardrum. As sound is picked by microphone 25 it isamplified by amplifier 34 and fed to receiver 43 which transform theelectrical ignal into acoustic energy at the acoustic output aperture 44of receiver 43. This acoustic energy travels through aperture 49 ofprotection plate 47 and energizes the eardrum of the user. It

will be noted that because of the aperture 49in protection plate 47 theacoustic output of receiver 43 is always traveling in the same acousticmedium, that is, air; and hence, there is not a large acoustic loss dueto a change in acoustic medium. Furthermore, since the microphonecompartment 12 and the amplifier compartment 14 are separated by thebattery compartment 33, any tendency for feed back between the amplifierand microphone is minimized.

It has been found that due to the large variance in the size of the earcanal of various users, it is sometimes difficult for users to keep thehearing aid, and particularly the boot 39 and receiver 4-3, in the earcanal. To overcome this problem various configuration tip 63 weredesigned to fit over boot 39. These tips 63 are made of very softrubber, or other suitable soft resilient material, and can be shaped toconform to the ear canal of the individual user. fitted to the boot 39and the users ear canal at'the time the hearing aid is purchased, thehearing aid can originally be manufactured with a standard size boot,and hence, the need for manufacturing hearing aids with various size andconfiguration boot and receiver members is eliminated.

It is to be understood that while I have shown a specific embodiment ofmy invention that this is for the purpose of illustration only and thatmy'invention is to be limited solely by the scope of the appendedclaims.

What I claim is: 1. An in-the-ear hearing aid comprising:

(a) a housing adapted to be fitted into the ear of the user, saidhousing containing a microphone and amplifier connected inoperable'relationship;

(b) a soft resilent elongated hollow boot having a first aperture at oneend thereof and a second aperture at the opposite end thereof, saidopposite end i of the boot being tapered and terminating in an externalilp; (c) an elongated receiver member capable of producing an acousticoutput from one end thereof, said receiver being mounted inside of saidhollow resilient Since the soft resilient tips 63 can be' boot so thatthe acoustic output end of said receiver is adjacent the first apertureof said boot, the boot and receiver adapted for insertion in the earcanal of the user with the first aperture adjacent the eardrum of theuser;

(d) a third aperture through the wall of said housing, the diameter ofsaid third aperture being less than the'normal diameter of the exteriorlip of said boot, said otherend of the boot being positioned throughsaid third aperture and held therein by said exterior lip;

(e) a locking member comprising a knob portion separated from one faceof a plate by means of a shaft portion, the maximum diameter of the knobportion being less than the diameter of said third aperture but greaterthan the normal diameter of said second aperture, the diameter of saidshaft portion being substantially equal to the diameter of said secondaperture, and the diameter of said plate being larger than the diameterof said third aperture,

said locking member'having a fourth aperture extending through the plateand shaft and knob portions thereof, the knob portion of said lockingmember being'forced through the second aperture of said boot to lock theother end of the boot in said third aperture;

(f) and conductor means extending through said fourth aperture andconnecting'the output of said amplifier to said receiver.

2. An in-the-ear hearing aid comprising:

(a) a'housing adapted to be fitted into the ear of the user, saidhousing containing a microphone and amplifier connected in operablerelationship;

(b) an elongated hollow boot having a first aperture at one end thereofand a second aperture at the opposite end thereof, said opposite end ofthe boot being tapered and terminating in an external lip;

(c) an elongated receiver member capable of producing an acoustic outputfrom one end thereof, said receiver being mounted inside of said hollowresilient boot so that the acoustic output end of said receiver isadjacent the first aperture of said boot, the boot and receiver adaptedfor insertion in the ear canal of the user with the second apertureadjacent the eardrum of the user;

(d) a third aperture through the wall of said housing, the diameter ofsaid third aperture being less than V the normal diameter of theexterior lip of said boot, said other end of the boot being positionedthrough said third aperture and held therein by said exterior p;

(e) a locking member comprising a knob portion separated from one faceof a plate by means of a shaft portion, the maximum diameter of the knobportion being less than the diameter of said third 7 aperture butgreater than the normal diameter of said second aperture, the diameterof said shaft portion substantially equal to the diameter of said secondaperture, and the diameter of said plate being larger than the diameterof said third aperture, said locking member having a fourth apertureextending through the plate and shaft and knob portions thereof, theknob portion of. said locking member being forced through the secondaperture of said boot to lock the other end of the boot in said thirdaperture;

(f) conductor means extending through said fourth aperture andconnecting the output of said amplifier to said receiver;

(g) and a soft resilient tip fitted over the boot and receiver and;fitted to the shape of the ear canal of the user to hold said boot andreceiver therein.

3. An in-the-ear hearing aid'comprising:

(a) a housing adapted to be fitted into the ear of the user, saidhousing being divided into first and second end compartments and'acenter compartment;

(b) a first aperture through one of the outer Walls of said first endcompartment;

(c) a microphone mounted in said first end compartment adjacent saidfirst aperture;

(d) an amplifier mounted in said second end compartment, said amplifierhaving an input and an output;

(e) means connecting said microphone to the input of said amplifier;

(f) a batter"; mounted in said center compartment and connected to saidamplifier to provide an energizing source for the amplifier;

(g) an elongated receiver member capable of producing an acoustic outputfrom one end thereof and adapted for insertion in the ear canal of theuser with said one end adjacent the eardrum of the user;

(h) a second aperture through one of the outer Walls of said second endcompaartment;

(i) means pivotally mounting the other end of said receiver to saidhousing adjacent said second aperture;

(j) conductor means extending through said second aperture andconnecting the output of said amplifier to said receiver;

(k) and a soft resilient tip fitted over the receiver and fitted to theshape of the ear canal of the user to hold said receiver therein.

4. An in-the-ear hearing aid comprising:

(a) a housing adapted to be fitted into the ear of the user;

(b) a first aperture through one of the walls of said housing;

(c) a microphone in said housing adjacent said first aperture;

(d) an amplifier mounted in said housing, said amplifier having an inputand an output;

(e) means connecting said microphone to the input of said amplifier;

(f) a battery mounted in said housing and connected to said amplifier toprovide an energizing source therefor;

(g) a soft resilient elongated hollow boot having a second aperture atone end thereof and a third aperture at the opposite end thereof, saidopposite end of the boot being tapered and terminating in an externallip;

(h) an elongated receiver member capable of producing an acoustic outputfrom one end thereof, said receiver being mounted inside of said hollowresilient boot so that the acoustic output end of said receiver isadjacent the second aperture of said boot, said boot and receiveradapted for insertion in the ear canal of the user with the secondaperture adjacent the eardrum of the user;

(i) a fourth aperture through one of the walls of said housing, saidother end of the boot being positioned through said fourth aperture;

(j) locking means connected to prevent Withdrawal of said other end ofthe boot from said fourth aperture;

(k) and conductor means extending through said third aperture andconnecting the output of said amplifier to said receiver.

5. An inthe-ear hearing aid comprising:

(a) a housing adapted to be fitted into the ear of the user, saidhousing being divided into first and second end compartments and acenter compartment;

(b) a first aperture through one of the outer walls of said first endcompartment;

(c) a microphone mounted in said first end compart merit adjacent saidfirst aperture;

(d) an amplifier mounted in said second end compartment, said amplifierhaving an input and an output;

(e) means connecting said microphone to the input of said amplifier;

(f) a battery mounted in said center compartment;

g) conducting means connecting said battery to said U amplifier toprovide an energizing source for the amplifier;

(h) a soft resilient elongated hollow boot having a.

second aperture at one end thereof and a third aperture at the oppositeend thereof, said opposite end of the boot being tapered and terminatingin an external lip;

(i) an elongated receiver member capable of producing an acoustic outputfrom one end thereof, said receiver being mounted inside of said hollowresilient boot so that the acoustic output end of said receiver isadjacent the second aperture of said boot, said boot and receiveradapted for insertion in the ear canal of the user with the secondaperture adjacent the eardrum of the user;

(j) a fourth aperture through one of the outer Walls of said second endcompartment, diameter of said fourth aperture being less than the normaldiameter of the exterior lip of said boot, said other end of the bootbeing positioned through said fourth aperture and held therein by saidexterior lip;

(la) a locking member comprising a knob portion separated from one faceof a plate by means of a shaft portion, the maximum diameter of the knobportion being less than the diameter of said fourth aperture but greaterthan the normal diameter of said third aperture, the diameter of saidshaft portion being substantially equal to the diameter of said thirdaperture, and the diameter of said plate being larger than the diameterof said fourth aperture, said looking member having a fifth apertureextending through the plate and shaft and knob portions thereof, theknob portion of said locking member being forced through the thirdaperture of said boot to lock the other end of the boot in said fourthaperture;

(1) and conductor means extending through said fifth aperture andconnecting the output of said amplifier to said receiver.

ti. An in-the-ear hearing aid comprising:

(a) a housing adapted to be fitted into the ear of the user;

(b) a first aperture through one of the Walls of said housing;

(c) a microphone mounted in said housing adjacent said first aperture;

(d) an amplifier mounted in said housing, said amplifier having an inputand an output;

(e) means connecting said microphone to the input of said amplifier;

(f) a battery mounted in said housing and connected to said amplifier toprovide an energizing source therefor;

(g) a soft resilient elongated hollow boot having a second aperture atone end thereof and a third aperture at the opposite end thereof, saidopposite end of the boot being tapered and terminating in an externallip;

(h) an elongated receiver member capable of producing an acoustic outputfrom one end thereof, said receiver being mounted inside of said hollowresilient boot so that the acoustic output end of said receiver isadjacent the second aperture of said boot, said boot and receiveradapted for insertion in the ear canal of the user with the secondaperture adjacent the eardrum of the user;

(i) a rigid protection plate mounted in the second aperture of saidboot, said protection plate having a fourth aperture therethrough;

(j) a fifth aperture through one of the walls of said housing, thediameter of said fifth aperture being less than the normal diameter ofthe exterior lip of said boot, said other end of the boot beingpositioned through said fifth aperture and held there in by saidexterior lip;

(k) a locking member comprising a knob portion separated from one faceof a plate by'means of a shaft portion, the maximum diameter of the knobportion being less than the diameter of said fifth aperture but greaterthan the normal diameter of said third aperture, the diameter of saidshaft portion being substantially equal to the diameter of said thirdaperture, and the diameter of said plate being larger than the diameterof said fifth aperture, said locking member having a sixth apertureextending through the plate and shaft and knob portions thereof, theknob portion of said locking member being forced through the thirdaperture of said boot to lock the other end of the boot in said fifthaperture;

(1) and conductor means extending through said sixth aperture andconnecting the output of said amplifier to said receiver.

7. An in-the-ear hearing aid comprising: 7

(a) a housing adapted to be fitted into the ear of the user, saidhousing being divided into first and second end compartments and acenter compartment;

(b) a first aperture through one of the outer walls of said first endcompartment;

(c) a microphone mounted in said first end compart- I ment adjacent saidfirst aperture;

(d) an amplifier mounted in said second end compartment, said amplifierhaving an input and an output;

(e) means connecting said microphone to the input of said amplifier;

(f) a battery mounted in said center compartment;

(g) conducting means connecting said battery to said amplifier toprovide an energizing source for the amplifier;

(h) a soft resilent elongated hollow boot having a second aperture atone end thereof and a third aperture at the opposite end thereof, saidopposite end of the boot being tapered and terminating in an externallip;

(i) an elongated receiver member capable of producing an acoustic outputfrom one end thereof, said receiver being mounted inside of said hollowresilient boot so that the acoustic output end of said receiver isadjacent the second aperture of saidpboot, said boot and receiveradapted for insertion inzthe ear canal of the user with the secondaperture adjacent the eardrum of the user;

(j) a fourth aperture through one of the outer walls of said second endcompartment, diameter of said fourth aperture being less than the normaldiameter of the exterior lip of said boot, said other end of the bootbeing positioned through said fourth aperture and held therein by saidexterior lip;

(k) locking means connected to said other end of the boot to preventwithdrawal of the boot from said fourth aperture; V

'(l) and conductor means connecting the output of said (a) a housingadapted to be fitted into the ear of the user, said housing beingdivided into first and second end compartments and a center compartment;(b) a first aperture through one of the outer walls of said first endcompartment; V (c) a microphone mounted in said first end compartmentadjacent said first aperture; (d) an amplifier mounted in said secondend compartment, said amplifier having an input and an output; (e) meansconnecting said microphone to the input of said amplifier; 7 (f)conducting plates mounted on the Walls of said center compartmentseparating the center compartment from said first and second endcompartments; g) a Wafer type battery mounted in said center compartmentin electrical contact with said conducting plates; a

(h) conducting means connecting said conducting plates to said amplifierto provide an energizing source for the amplifier; 7 a

(i) a soft resilient elongated hollow boot having a second aperture atone end thereof and a third aperture at the opposite end thereof, saidopposite end of the boot being tapered and terminating in an externallip; r t

(j) an elongated receiver member capable of producing an acoustic outputfrom one end thereof, said receiver being mounted inside of said hollowresilient boot so that the acoustic output end of said receiverisadjacent, the second aperture of said boot, the boot and receiveradapted for insertion in the ear canal of the user with the secondaperture adjacent the eardrum of the user;

(k) a rigid protection plate mounted in the second aperture of saidboot, said protection plate having a fourth aperture therethrough;

(l) a fifth aperture through one of the outer walls of said second endcompartment, the diameter of said fifth aperture being less than thenormal diameter of the exterior lip ofsaid boot, said other end of theboot being positioned through said fifth aperture and held therein bysaid exterion lip; I

(m) a locking comprising a knob portion separated from one face of aplate by means of a shaft portion, the maximum diameter of the knobportion being less than the diameter of said fifth aperture but greaterthan the normal diameter of said third aperture, the diameter of saidshaft portion being substantially equal to the diameter of said thirdaperture, and the diameter of said plate being larger than the diameterof said fifth aperture, said locking member having a sixth apertureextending through the plate and shaft and knob portions thereof, theknob portion of said locking member being forced through the thirdaperture of said boot to lock the other end of the boot in said fifthaperture;

(n) and conductor means extending through said sixth aperture andconnecting the output of said amplifier to the receiver.

9. An in-the-ear hearing aid comprising:

(a) a housing adapted to be fitted into the ear of the user, saidhousing being divided into first and'second end compartments and acenter compartment;

(b) a first aperture through'one of the outer walls of said firstrendcompartment; 7

(c) a microphone mounted in said first end compartment adjacent saidfirst aperture;

(d) an amplifier mounted in said second end compartment, said amplifierhaving an input and an output;

(e) means cormecting said microphone to the input of said amplifier;

(f) conducting plates mounted on the walls of said center compartmentseparating the center compart: ment from said first and second endcompartments;

(g) a wafer type battery mounted in said center compartment inelectrical contact with said conducting plates; 7 V

(h) conducting means connecting said conducting plates to said amplifierto provide an energizing source for the amplifier;

(i) a soft resilient elongated hollow boot havinga second aperture atone end thereof and a third aperture at the opposite end thereof, saidoppositeend of the boot being tapered and terminating in an externallip;

(3') an elongated receiver member capable of producing an acousticoutput from one end thereof, said receiver being mounted inside of saidhollow resilient boot so that the acoustic output end of said receiveris adjacent the second aperture of said boot, said boot and receiveradapted for insertion in the ear canal of the user with the secondaperture adjacent the eardrum of the user;

(lc) a rigid protection plate mounted in the second (11) conductor meansextending through said sixth aperaperture of said boot, said protectionplate having a ture and connecting the output of said amplifier tofourth anerture therethrough; said receiver;

(1) a fifth aperture through one of the outer Walls of (o) and a softresilient tip fitted over the boot and resaid second end compartment,diameter of said fifth 5 cfiivfif and fitted the Shell)6 of the ear$31181 0f the aperture being less than the normal diameter of the 1155!W h Said boot F K thawinexterior lip of said boot, said other end of theboot In an fl e ring aid having an elongated being positioned throughsaid fifth aperture and held recfilver Capable of Producmg P energy fromone herein by said exterior MD; end thereof and adapted for insertion 1nthe ear canal of (rn) a lockin member coin risin EllQlOb portion sep- 10ms .user Said one end i the eardrum Sald 5 f A s r f E ft receiver beingcovered bya soft resilient elongated hollow i p 1a y means a boot havingan anerture adjacent said one end of said portion, the maximum diameterof the knob portion receiver, the improvement comprising:

a soft resilient tip removably fitted over said resilient 15 boot andfitted to the shape of the ear canal of the user to hold said bootcovered receiver therein. stantially equal to the diameter of saidfourth aper- Reiemmes Cited by the Examiner ture, and the orameter ofsaid plate being larger than the diameter of said fifth aperture, saidlocking mem- UNITED STATES PATENTS her having a sixth aperture extendingthrough the 20 2, 7,9 1 Au rt et a1 179-l07 plate and shaft and knobportions thereof, the knob FOREIGN PATENTS portion of said lockingmember being forced through a the fourth aperture of said boot to lockthe other end 6/61 Germany of the boot in said fifth aperture; ROBERT H.ROSE, Primary Examiner.

being less than the diameter of said fifth aperture but greater than thenormal diameter of said fourth aperture, the diameter of said shaftportion being sub-

1. AN IN-THE-EAR HEARING AID COMPRISING: (A) A HOUSING ADAPTED TO BEFITTED INTO THE EAR OF THE USER, SAID HOUSING CONTAINING A MICROPHONEAND AMPLIFIER CONNECTED IN OPERABLE RELATIONSHIP; (B) A SORT RESILENTELONGATED HOLLOW BOOT HAVING A FIRST APERTURE AT ONE END THEREOF AND ASECOND APERTURE AT THE OPPOSITE END THEREOF, SAID OPPOSITE END OF THEBOOT BEING TAPERED AND TERMINATING IN AN EXTERNAL LIP; (C) AN ELONGATEDRECEIVER MEMBER CAPABLE OF PRODUCING AN ACOUSTIC OUTPUT FROM ONE ENDTHEREOF, SAID RECEIVER BEING MOUNTED INSIDE OF SAID HOLLOW RESILIENTBOOT SO THAT THE ACOUSTIC OUTPUT END OF SAID RECEIVER IS ADJACENT THEFIRST APERTURE OF SAID BOOT, THE BOOT AND RECEIVER ADAPTED FOR INSERTIONIN THE EAR CANAL OF THE USER WITH THE FIRST APERTURE ADJACENT THEEARDRUM OF THE USER; (D) A THIRD APERTURE THROUGH THE WALL OF SAIDHOUSING, THE DIAMETER OF SAID THIRD APERTURE BEING LESS THAN THE NORMALDIAMETER OF THE EXTERIOR LIP OF SAID BOOT, SAID OTHER END OF THE BOOTBEING POSITIONED THROUGH SAID THIRD APERTURE AND HELD THEREIN BY SAIDEXTERIOR LIP; (E) A LOCKING MEMBER COMPRISING A KNOB PORTION SEPARATEDFROM ONE FACE OF A PLATE BY MEANS OF A SHAFT PORTION, THE MAXIMUMDIAMETER OF THE KNOB PORTION BEING LESS THAN THE DIAMTER OF SAID THIRDAPERTURE BUT GREATER THAN THE NORMAL DIAMETER OF SAID SECOND APERTURE,THE DIAMETER OF SAID SHAFT PORTION BEING SUBSTANTIALLY EQUAL TO THEDIAMETER OF SAID SECOND APERTURE, AND THE DIAMETER OF SAID PLATE BEINGLARGER THAN THE DIAMETER OF SAID THIRD APERTURE, SAID LOCKING MEMBERHAVING A FOURTH APERTURE EXTENDING THROUGH THE PLATE AND SHAFT AND KNOBPORTIONS THEREOF, THE KNOB PORTION OF SAID LOCKING MEMBER BEING FORCEDTHROUGH THE SECOND APERTURE OF SAID BOOT TO LOCK THE OTHER END OF THEBOOT IN SAID THIRD APERTURE; (F) AND CONDUCTOR MEANS EXTENDING THROUGHSAID FOURTH APERTURE AND CONNECTING THE OUTPUT OF SAID AMPLIFIER TO SAIDRECEIVER.